How long do aerosol cans last?
Similarly one may ask, how long does a spray can last?
It was kept in a heated garage for 3 years. One can was used a year ago or so and I did some testing with it. After some shaking it sprayed fairly decent. I know Seymour says the shelf is only 2 years.
Also to know is, how do you fix an aerosol can that won't spray?
Place the nozzle back on the spray can and hold the can upside down, spraying it away from you. If that doesn't clear the nozzle, place the nozzle on a can of spray lubricant and spray the liquid through it, then place the nozzle back on the paint can.
There are three likely reasons. The nozzle has clogged. This often happens with spray paint or anything that turns hard or sticky when dry. For these kinds of materials, it is a good idea to turn the can upside down and spray for 3-5 seconds after each use to clear the nozzle.